Example Load Calculations Using the Standard Method:
Given:

Answers;
(inputs and calculated values are in red)
1. General Lighting & Receptacle Loads. NEC 2203(b) Not including open porches, garages, unused or unfinished spaces not adaptable for future use 
3 VA x 3700 (sq. ft.) 
1  11,100  
2. Small Appliance Branch
Circuits. NEC 22016(a) Al least 2 small appliances branch circuits must be included. NEC 21011(c)1 
1500 VA x 5 (min. 2) 
2  7,500  
3. Laundry Branch Circuit(s).
NEC 22016(b), 2204(c) At least 1 laundry branch circuit must be included. 
1500 VA x 2 (min. 1) 
3  3,000  
4. Add lines 1, 2 and 3  4  21,600  
5. 21,600 (line 4)  3000 = 18,600 VA 
5  18,600  
6. 18,600 (line 5) x 0.35= 6,510 VA 
6  6,510  
7. TOTAL General Lighting
and Receptacle Load 3000 + 6,510 (line 6) = 9,510 VA 
7  9,510  
8. FastenedInPlace Appliances. NEC 22017 Use nameplate rating. Do not include electric ranges, clothes dryers, spaceheating or A/C equipment 

If fewer than 4 units, place total voltamps (add the values) on line 8. 
8  7,925  
9. Clothes Dryers. NEC 22018 If not present >> skip. Otherwise, use 5000 watts or nameplate rating whichever is larger 
9  6,000  
10. Ranges, ovens, Cooktops and other cooking appliances over 1750 watts.
NEC 22019. If not present >> skip.
Otherwise, use Table 22019
along with notes A 7 kw cooktop and 6kw wall oven fall within col. "C" in Table 22019. Demand factor= 65%. Hence, (7kw+ 6kw) x 0.65= 8.45 kw, or 8450 watts (voltsamps) 
10  8,450  
11. Heating or Air Conditioning. NEC 22019.
Heating:
16 kw= 16,000 va + 4A x 115V= 460 va (air handlerblower)= 16,460 
11  16,460  
12. Largest motor (only one). NEC 22014, 43024 Multiply the largest motor voltamps x 25% Usually the airconditioner compressor is the largest motor. But since that appliance load was omitted, see step 11 above, use the next largest motor. In this case, the garbage disposal @ 1127 va. So 1127 x 0.25= 282 
12  282  
13. TOTAL VoltAmp Demand Load: Add lines 7 through 12  13  48,627  
14. MIN. Amperes for Service (Total va / voltage)= ( Line 13) / 240V (voltage= 240, for 120/240 V service)= 48,627 / 240V= 202 AMPS

14 
202
MIN. amps 

15. MIN. Size for Service Conductors/Feeders. NEC 2406(a). Use next STANDARD size fuse or breaker .  15  225 AMPS  
16. Size of Service and/or Feeder Conductors. Use NEC 31015(b) for the service conductors up to 400A. Rating > 400 amps; Use Table 31016 . MIN. SIZE of CONDUCTORS= 
16 
Use 3/0 CU, OR, 250 kcmil AL 

17. Size of Neutral Conductor. NEC 22022

17 
Use No. 2 CU See below for neutral sizing calcs) 

20. Size of Grounding Electrode Conductor (GEC). NEC, Table
25094
. MIN. SIZE of GEC: Based on 225 AMP service with 3/0 service conductors, the size of the GEC is No. 4 per Table 25094 
18 
No. 4 CU

Sizing the Neutral Conductor: Need to calculate all loads from appliances that contribute to the neutral. The neutral is sized by finding the max. unbalanced load.
GRAND TOTAL= 9,510+4,175+4200+5915+460+282= 24,542 VA A No, 2 CU (75º) is good
for 115 AMP per Table 31016 Note! The neutral conductor, No. 2 CU, is smaller than ServiceEntrance Conductors, No. 3/0, and larger than the Grounding Electrode Conductor, No. 4 CU. OK. 
va= voltsamperes=watts 